Mask system

ABSTRACT

A mask system includes a frame defining a breathing chamber, a cushion provided to the frame and adapted to form a seal with the patient&#39;s face, and a shroud provided to the frame and adapted to attach headgear. The shroud includes a retaining mechanism structured to connect the shroud to the frame. The retaining mechanism includes both a taper lock arrangement and a retaining clip arrangement.

This application is a continuation of U.S. application Ser. No.15/364,605, filed Nov. 30, 2016, now allowed, which is a continuation ofU.S. application Ser. No. 13/390,639, filed Feb. 15, 2012, now U.S. Pat.No. 9,539,403, which is the U.S. National Phase of InternationalApplication No. PCT/AU2009/001102, filed Aug. 26, 2009, each of which isincorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to a mask system used for treatment, e.g.,of Sleep Disordered Breathing (SDB) with Continuous Positive AirwayPressure (CPAP) or Non-Invasive Positive Pressure Ventilation (NIPPV).

BACKGROUND OF THE INVENTION

Patient interfaces, such as a full-face or nasal mask systems, for usewith positive airway pressure (PAP) devices in the treatment of sleepdisordered breathing (SDB), typically include a soft face-contactingportion, such as a cushion, and a rigid or semi-rigid shell or frame. Inuse, the interface is held in a sealing position by headgear so as toenable a supply of air at positive pressure (e.g., 2-30 cm H₂O) to bedelivered to the patient's airways.

One factor in the efficacy of therapy and compliance of patients withtherapy is the comfort and fit of the patient interface.

The present invention provides alternative arrangements of mask systemsto enhance the efficacy of therapy and compliance of patients withtherapy.

SUMMARY OF THE INVENTION

One aspect of the invention relates to a mask system including a framedefining a breathing chamber, a cushion provided to the frame andadapted to form a seal with the patient's face, and a shroud provided tothe frame and adapted to attach headgear. The shroud includes aretaining mechanism structured to connect the shroud to the frame. Theretaining mechanism includes both a taper lock arrangement and aretaining clip arrangement.

Another aspect of the invention relates to headgear for a mask systemincluding a pair of upper straps adapted to connect to an upper portionof the mask system, a pair of lower straps adapted to connect to a lowerportion of the mask system, and a cross bar to connect one of the upperstraps to one of the lower straps on each side of the patient's head.The cross bar limits relative movement of the upper and lower strapsrelative one another so as to maintain the upper strap in a positionaway from the patient's field of vision and allow a force vector appliedto upper strap to be directed towards the back of the patient's head inuse.

Another aspect of the invention relates to a mask system including aframe defining a breathing chamber, a cushion provided to the frame andadapted to form a seal with the patient's face, and a shroud provided tothe frame and adapted to attach headgear. The shroud includes upperheadgear connectors adapted to attach upper headgear straps and lowerheadgear connectors adapted to attach lower headgear straps. Each lowerheadgear connector includes a clip receptacle adapted to removablyinterlock with a headgear clip associated with a respective lowerheadgear strap. Each clip receptacle is connected to the shroud viaspaced-apart arm members that allow flexible movement of the clipreceptacle in use.

Another aspect of the invention relates to a mask system including aframe defining a breathing chamber, a cushion provided to the frame andadapted to form a seal with the patient's face, and upper headgearconnectors adapted to attach upper headgear straps and lower headgearconnectors adapted to attach lower headgear straps. Each upper headgearconnector includes an elongated arm and a slot at the free end of thearm adapted to receive a respective upper headgear strap and each lowerheadgear connector includes a clip receptacle adapted to removablyinterlock with a headgear clip associated with a respective lowerheadgear strap. The slot is oriented about 2-26° with respect to avertical axis of the frame.

Another aspect of the invention relates to a mask system including aframe defining a breathing chamber, a cushion provided to the frame andadapted to form a seal with the patient's face, and a shroud provided tothe frame and adapted to attach headgear. The shroud includes upperheadgear connectors adapted to attach upper headgear straps and lowerheadgear connectors adapted to attach lower headgear straps. Each lowerheadgear connector includes a clip receptacle adapted to removablyinterlock with a headgear clip associated with a respective lowerheadgear strap. Each clip receptacle is oriented about 2-12° withrespect to a vertical axis of the frame.

Other aspects, features, and advantages of this invention will becomeapparent from the following detailed description when taken inconjunction with the accompanying drawings, which are a part of thisdisclosure and which illustrate, by way of example, principles of thisinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings facilitate an understanding of the variousembodiments of this invention. In such drawings:

FIG. 1-1 is a perspective view of a mask system according to anembodiment of the present invention;

FIG. 1-2 is a side view of the mask system of FIG. 1-1 ;

FIG. 2-1 is a perspective view of the mask system of FIG. 1-1 withoutheadgear;

FIG. 2-2 is a side view of the mask system of FIG. 2-1 ;

FIG. 3-1 is a side view of the frame and upper headgear connector of themask system of FIG. 1-1 ;

FIG. 3-2 is a rear view of the frame and upper headgear connector ofFIG. 3-1 ;

FIG. 4-1 is a perspective view of the frame of the mask system of FIG.1-1 ;

FIG. 4-2 is a front view of the frame of FIG. 4-1 ;

FIG. 4-3 is a side view of the frame of FIG. 4-1 ;

FIG. 4-4 is a top view of the frame of FIG. 4-1 ;

FIG. 5-1 is a side view showing different sizes of the frame of FIG. 4-1, in overlapping relation;

FIG. 5-2 is a front view showing different sizes of the frame of FIG.4-1 , in overlapping relation;

FIGS. 6-1 to 6-6 are various views of an upper headgear connectoraccording to an embodiment of the present invention;

FIGS. 7-1 to 7-5 are various views of an upper headgear connectoraccording to an embodiment of the present invention;

FIG. 8-1 is a top view showing different sizes of the upper headgearconnector of FIG. 6-1 , in overlapping relation;

FIG. 8-2 is a top view showing different sizes of the upper headgearconnector of FIG. 6-1 , in spaced relation;

FIG. 8-3 is a side view showing different sizes of the upper headgearconnector of FIG. 6-1 , in overlapping relation;

FIG. 8-4 is a side view showing different sizes of the upper headgearconnector of FIG. 6-1 , in spaced relation;

FIG. 8-5 is a rear view showing different sizes of the upper headgearconnector of FIG. 6-1 , in overlapping relation;

FIG. 8-6 is a rear view showing different sizes of the upper headgearconnector of FIG. 6-1 , in spaced relation;

FIG. 8-7 is a front view showing different sizes of the upper headgearconnector of FIG. 6-1 , in overlapping relation;

FIG. 8-8 is a front view showing different sizes of the upper headgearconnector of FIG. 6-1 , in spaced relation;

FIGS. 9-1 and 9-2 show exemplary dimensions for a large size mask systemof FIG. 1-1 ;

FIGS. 9-3 and 9-4 show exemplary dimensions for a medium size masksystem of FIG. 1-1 ;

FIGS. 9-5 and 9-6 show exemplary dimensions for a small size mask systemof FIG. 1-1 ;

FIG. 10-1 is an enlarged front perspective view showing the frame andupper headgear connector of the mask system of FIG. 1-1 ;

FIG. 10-2 is an enlarged front perspective view showing the frame of themask system of FIG. 1-1 ;

FIG. 10-3 is an enlarged rear perspective view showing the upperheadgear connector of the mask system of FIG. 1-1 ;

FIG. 10-4 is an enlarged rear perspective view showing the frame andupper headgear connector of the mask system of FIG. 1-1 ;

FIG. 10-5 is a cross-sectional view showing the frame and upper headgearconnector of the mask system of FIG. 1-1 ;

FIG. 10-6 is a cross-sectional view showing the frame and upper headgearconnector of the mask system of FIG. 1-1 ;

FIG. 10-7 is a cross-sectional view showing the frame, cushion, andupper headgear connector of the mask system of FIG. 1-1 ;

FIG. 11-1 is a front perspective view of a mask system according toanother embodiment of the present invention;

FIG. 11-2 is a side perspective view of the mask system of FIG. 11-1 ;

FIGS. 12-1 to 12-4 are various views of a mask system according toanother embodiment of the present invention;

FIGS. 13-1 to 13-4 are various views of the frame and shroud of the masksystem of FIG. 12-1 ;

FIGS. 14-1 to 14-4 are various views of the shroud of the mask system ofFIG. 12-1 ;

FIG. 15-1 is a top view of the frame and shroud of the mask system ofFIG. 12-1 showing flexibility of the lower headgear connectors;

FIGS. 15-2 and 15-3 are bottom and front views of the mask system ofFIG. 12-1 showing flexibility of the lower headgear connectors;

FIGS. 15-4 and 15-5 are front and side views of the mask system of FIG.12-1 showing flexibility of the lower headgear connectors in use;

FIG. 16-1 is a cross-sectional view of the frame and shroud of the masksystem of FIG. 12-1 ; and

FIG. 16-2 is an enlarged top view of the frame and shroud of the masksystem of FIG. 12-1 .

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

The following description is provided in relation to several embodimentswhich may share common characteristics and features. It is to beunderstood that one or more features of any one embodiment may becombinable with one or more features of the other embodiments. Inaddition, any single feature or combination of features in any of theembodiments may constitute additional embodiments.

In this specification, the word “comprising” is to be understood in its“open” sense, that is, in the sense of “including”, and thus not limitedto its “closed” sense, that is the sense of “consisting only of”. Acorresponding meaning is to be attributed to the corresponding words“comprise”, “comprised” and “comprises” where they appear.

The term “air” will be taken to include breathable gases, for exampleair with supplemental oxygen.

The term “shroud” will be taken to include components that partially orfully cover a second component within the illustrated embodiments. In anembodiment, the shroud may include the component that partially coversor is mounted on the frame components of the illustrated embodiments.

1. Mask System

As described in greater detail below, the mask system includes a frame,a cushion provided to the frame and adapted to form a seal with thepatient's face, a shroud provided to the frame and adapted to attachheadgear, and an elbow provided to the frame and adapted to be connectedto an air delivery tube that delivers breathable gas to the patient.Headgear may be removably attached to the top and bottom of the frameeither directly or via the shroud, which provides headgear connectionpoints for headgear positioned and arranged to stably maintain the masksystem in position on the patient's face. The mask system is intendedfor use in positive pressure therapy for users with Obstructive SleepApnea (OSA) or another respiratory disorder.

While each embodiment below is described as including a full-face ororo-nasal interface type, each embodiment may be adapted for use withother suitable interface types. That is, the interface type is merelyexemplary, and each embodiment may be adapted to include other interfacetypes, e.g., nasal interface, nasal mask, nozzles, nasal prongs, etc.

Also, each illustrated embodiment includes features that may be usedwith the embodiments and/or components described in PCT Application No.PCT/AU2009/000241, filed Feb. 27, 2009, as would be apparent to those ofordinary skill in the art. The above noted application is incorporatedherein by reference in its entirety. However, it should be appreciatedthat any single feature or combination of features in any of theembodiments may be applied to other suitable mask arrangements.

1.1 Frame

As shown in FIGS. 1-1 to 4-4 , the frame 20 of the mask system 10 isstructured to maintain the cushion 40, shroud 50, and elbow 60 in anoperative position with respect to the patient's face.

The frame 20 defines a breathing chamber or cavity adapted to receivethe patient's nose and mouth and provide air communication to thepatient. One or lower portion of the frame includes an opening 22adapted to receive or otherwise communicate with the elbow 60 (e.g.,swivel elbow) and another or upper portion of the frame includes anopening 81 to support a vent arrangement 80 (e.g., see FIGS. 1-1 to 2-2) for gas washout. In an embodiment, the vent arrangement 80 may beintegrally formed in one piece with the frame. Also, the upper portionof the frame includes an interfacing structure adapted to interface orotherwise removably connect to the shroud 50, as described in greaterdetail below.

In an alternative embodiment, the lower portion of the frame may alsoinclude an interfacing structure adapted to interface or otherwiseremovably connect to the shroud (e.g., see FIG. 16-1 described below).

1.1.1 Lower Headgear Connectors

In the embodiment of FIGS. 1-1 to 4-4 , the bottom or lower portion ofthe frame 20 includes lower headgear connectors 30 adapted to attachheadgear. The lower headgear connectors 30 may be integrally formed inone-piece with the frame. Each lower headgear connector 30 includes aclip receptacle 32 adapted to be removably interlocked with a headgearclip 34 associated with a respective headgear strap. The clips allow foreasier positioning or donning/removal of the mask system.

In an embodiment, the headgear clip receptacle and clip may be similarto that on ResMed's Mirage Quattro™ mask or ResMed's Mirage Liberty™mask. Exemplary clip arrangements are disclosed in U.S. PatentPublication Nos. 2007/0157353 and 2006/0283461, each of which isincorporated herein by reference in its entirety.

The frame may be provided in different sizes, e.g., small, medium, andlarge. As shown in FIGS. 5-1 and 5-2 , the position of the clipreceptacles 32 may change or vary between sizes, e.g., shift vertically.The positioning of the receptacles may be selected to enhance sealing,e.g., by changing the application point for headgear tension.

1.1.2 Vent Arrangement

As best shown in FIGS. 1-1 to 2-2, 10-1, 10-2, and 10-4 , the ventarrangement 80 is in the form of a diffused vent cap that may beintegrally formed in one-piece with the frame 20. The vent cap includesa base wall 82, a dome 84 that extends upwardly from the base wall 82above the horizontal surface of the base wall 82, and multiple ventholes 86 arranged on an annular side wall of the dome 84 to providediffuse airflow that is directed away from the patient's face as well asthe bed partner (e.g., see FIGS. 10-1 and 10-4 ). The angle of thediffused airflow can be tuned by altering the dimensions of the ventcap. The diffused airflow provides venting over a larger area tominimize jetting and may also reduce noise.

In the illustrated embodiment, as shown in FIG. 1-2 , the vent cap 80directs exhaust flow up and out from the mask, e.g., angle α is about0-30°, e.g., 15°, 20°. In an embodiment, angle α is about 20° to ensurethat air is not directed onto the patient's face.

In the illustrated embodiment, the vent holes 86 are arranged radiallyalong the annular side wall of the dome 84 to radially divide theexhaust flow in 360°. In an embodiment, the vent cap may include 10-40vent holes, e.g., 25 vent holes.

In the illustrated embodiment, the diameter of the vent cap (when viewedfrom above) is about 10-25 mm, e.g., 18 mm.

Further details and/or alternative arrangements of such vent arrangementare disclosed in U.S. Patent Application Publication No. US 2009/0050156A1, which is incorporated herein by reference in its entirety.

However, it should be appreciated that the vent arrangement may includeother suitable arrangements, e.g., different number of holes, holearrangement, positioning on frame, etc. Also, it should be appreciatedthat the vent arrangement may be in the form of a vent insert (e.g.,elastomeric vent insert) that is adapted to be removably supportedwithin an outlet opening in the frame. In addition, it should beappreciated that the vent arrangement may be provided to the elbow.

1.2 Shroud

The shroud is connected to the frame and is structured to attachheadgear to the mask system. The shroud may be constructed (e.g.,injection molded) of resilient material including, but not limited to,plastics (such as Nylon or Nylon 12) or non-plastics. The shroud may beconstructed of any suitable material which could also include: textiles,polycarbonate, polypropylene, thermoplastic elastomer (TPE), or Pocan®,etc.

1.2.1 Upper Headgear Connector or Rigidizer

In the embodiment of FIGS. 1-1 to 3-2 , the shroud 50 is in the form ofa snap-on upper headgear connector or upper headgear rigidizer that isconnected to the top of the frame 20 and is structured to attach upperheadgear straps to the frame. This shroud is used in conjunction withthe frame 20 including lower headgear connectors 30 adapted to attachlower headgear straps to the frame.

As best shown in FIGS. 6-1 to 6-6 , the upper headgear rigidizer 50includes a frame connecting portion 52 adapted to connect the upperheadgear rigidizer to the frame. The frame connecting portion 52 isadapted to connect to the frame at a position proximal to the nasalbridge region or nose of the patient. The frame connecting portion 52includes a contoured or general “U” shape to accommodate the ventarrangement 80 provided to the frame 20. Further details of connectionare described below.

The upper headgear rigidizer 50 also includes arms 54 that extend fromrespective sides of the frame connecting portion 52. Each arm 54includes a slot or receiving hole 55 at the free end thereof adapted toreceive a respective headgear strap. In use, the arms 54 extend aroundthe face of the patient in a generally concave angle below the eyes ofthe patient so as to avoid the patient's field of view, i.e., directheadgear away from the patient's eyes. The hole 55 may alternately bereplaced with a series or plurality of holes to provide for increasedadjustability.

FIGS. 11-1 and 11-2 illustrate an upper headgear rigidizer 50 accordingto an alternative embodiment. In this embodiment, the arm 54 isabbreviated or relatively short.

Preferably, the rigidizers may function to modify the force vectorsacting on the mask system. In these embodiments, the rigidizer providesan attachment point for the headgear at the upper most extreme of themask system, while simultaneously providing a means to avoid theheadgear straps from entering or impeding the patient's field of vision.The rigid connection between the rigidizer and the top of the masksystem allows adjustments to the headgear to be transmitted to the topof mask system via the rigidizer. Additionally, the rigidizer may act asa type of lever to provide a mechanical advantage to any turning forceapplied to them.

1.2.2 Different Sizes

The upper headgear rigidizer 50 may be provided in different sizes,e.g., small, medium, and large, e.g., for use with different size framesas described above or a one size fits all type of frame. For example, asshown in FIGS. 8-1 to 8-8 , the size, angle, and/or orientation of thearms may vary or change between sizes.

As shown in FIGS. 9-1 and 9-2 , a large size upper headgear rigidizermay include the following dimensions: d1 of about 120-180 mm (e.g., 153mm), d2 of about 116-136 mm (e.g., 126 mm), d3 of about 107-127 mm(e.g., 117 mm), d4 of about 68-88 mm (e.g., 78 mm), d5 of about 88-108°(e.g., 98°), d6 of about 28-48° (e.g., 38°), d7 of about 98-118 mm(e.g., 108 mm), d8 of about 59-79 mm (e.g., 69 mm), d9 of about 39-59 mm(e.g., 49 mm), d10 of about 35-55 mm (e.g., 45 mm), and d11 of about6-26° (e.g., 16°).

As shown in FIGS. 9-3 and 9-4 , a medium size upper headgear rigidizermay include the following dimensions: d1 of about 120-163 mm (e.g., 148mm), d2 of about 113-133 mm (e.g., 123 mm), d4 of about 66-86 mm (e.g.,76 mm), d5 of about 92-112° (e.g., 102°), d6 of about 34-54° (e.g.,44°), d7 of about 88-108 mm (e.g., 98 mm), d8 of about 57-77 mm (e.g.,67 mm), d9 of about 33-53 mm (e.g., 43 mm), d10 of about 33-53 mm (e.g.,43 mm), and d11 of about 2-22° (e.g., 12°).

As shown in FIGS. 9-5 and 9-6 , a small size upper headgear rigidizermay include the following dimensions: d1 of about 115-160 mm (e.g., 126mm), d2 of about 94-114 mm (e.g., 104 mm), d4 of about 68-88 mm (e.g.,78 mm), d5 of about 56-76° (e.g., 66°), d6 of about 34-54° (e.g., 44°),d7 of about 86-106 mm (e.g., 96 mm), d8 of about 49-69 mm (e.g., 59 mm),d9 of about 29-49 mm (e.g., 39 mm), d10 of about 29-49 mm (e.g., 39 mm),and d11 of about 2-22° (e.g., 12°).

It is noted that dimension d1 for the different sizes is a width of thearms and relates to fit across face widths. It is noted that dimensiond7 for the different sizes relates to fit and clearance between thepatient's eyes/ears. It is noted that dimension d11 for the differentsizes relates to the headgear force vector (indicated as a dashed arrowin FIGS. 9-2, 9-4 , and 9-6). In an embodiment, the arms may becontoured or flexed such that the arms lay substantially flat orhorizontal (when viewed from the top such as FIG. 9-1 ), e.g., toaccommodate largest face range.

1.2.3 Upper and Lower Headgear Connectors

FIGS. 12-1 to 16-2 illustrate a mask system 210 including a shroud 250with both upper and lower headgear connectors 251, 231. The shroud 250is used in conjunction with the frame 220 including no integral headgearconnectors.

As illustrated, the top end of the shroud 250 is adapted to bepositioned proximal to the nasal bridge region or nose of the patientand the bottom end is adapted to be positioned proximal to the mouth orchin of the patient (e.g., see FIGS. 15-4 and 15-5 ). The top end of theshroud includes an opening or vent receiving hole 258 to accommodate thevent arrangement 280 provided to the frame, and the bottom end includesan opening or elbow hole 259 to accommodate the elbow 260.

The upper headgear connectors 251 extend from each side of the top end,and the lower headgear connectors 231 extend from each side of the lowerend. The headgear connectors 251, 231 may be integrally molded orotherwise attached to the shroud.

Each upper headgear connector 251 includes a curved arm 254 and a slotor receiving hole 255 as described above. The hole 255 may alternatelybe replaced with a series or plurality of holes to provide for increasedadjustability.

Each lower headgear connector 231 includes a clip receptacle 232 adaptedto be removably interlocked with a headgear clip 234 associated with arespective headgear strap. Each clip receptacle 232 is connected to theshroud via spaced-apart arm members 233, e.g., “wishbone” connection. Asshown in FIGS. 15-1 to 15-3 , the shroud 250 is molded such that the armmembers 233 support the clip receptacles 232 in a raised or spacedposition with respect to the frame 220 when no headgear tension isapplied. Upon the application of headgear tension, the arm members 233allow the clip receptacles 232 to flex towards and into contact with theframe 220 in use, e.g., to position the force vectors. FIGS. 15-4 and15-5 show the mask system 210 in position on the patient's head in use.

FIGS. 15-2 and 15-3 show exemplary angles/force vectors provided by theclip receptacles when the mask system is worn by the patient. It isnoted that such angles/force vectors may be consistent across all sizesof the shroud, e.g., small, medium, and large. In the embodiment shownin FIGS. 15-2 and 15-3 , a1 may be about 40-50°, e.g., 45°, and a2 maybe about 2-12°, e.g., 7°. However, other dimensions are possible.

Also, it is noted that the upper headgear connector 251 of the shroud250 may include similar dimensions as described above with respect tothe embodiment of the upper headgear connector 50 of FIGS. 9-1 to 9-6 ,for small, medium, and large sizes.

1.2.4 Arm Padding

In an embodiment, the arms 54, 254 may be used to stabilize the masksystem by contacting the patient's face at the cheeks. As shown in FIGS.1-1 to 2-2 and 12-1 to 12-4 , the arms 54, 254 of the upper connectors50, 251 may be enveloped in a soft fabric sleeve or padded material 90to act as padding against the cheeks of the patient, e.g., for patientfacial comfort. The soft fabric sleeve 90 may be in the configuration ofan elastic tube or sock covering a portion of the arms.

Also, the arms 54, 254 may be structured to retain the sleeve 90thereon, e.g., prevent relative movement between the sleeve and arm. Forexample, as shown in FIGS. 14-1 to 14-4 , the distal end of the arm(providing the slot) includes an enlarged head which provides a shoulder257(1) for retaining an end of the sleeve. In addition, the proximal endof the arm includes a widened portion which provides a shoulder 257(2)for retaining the other end of the sleeve.

1.3 Headgear

Headgear may be removably attached to the headgear connectors tomaintain the mask system in a desired position on the patient's face.

As shown in FIGS. 1-1 and 1-2 , the headgear 70 includes a pair of upperstraps 72 and a pair of lower straps 74 with the upper straps 72removably attached to respective upper headgear connectors 50 and thelower straps 74 removably attached to respective lower headgearconnectors 30. The free end of each strap 72, 74 may include a Velcro®tab structured to engage the remainder of the strap to secure the strapin place. Such Velcro® attachment also allows adjustment of the lengthof the straps. However, the upper and lower headgear straps may besecured to the headgear connectors in any other suitable manners, e.g.,adjustable ladder-lock arrangement, etc.

The upper straps 72 split at the crown of the patient's head to a topstrap 75 adapted to pass over the top of the patient's head in use and arear strap 76 adapted to pass behind the patient's head in use. Sucharrangement may help to realign the upper headgear vectors to preventthe mask system from sliding up the patient's face in use.

FIGS. 15-4 and 15-5 illustrate similar headgear 70 attached to theheadgear connectors 251, 231 of the shroud 250 of mask system 210.

FIGS. 11-1 and 11-2 illustrate headgear according to an alternativeembodiment. In this embodiment, a cross bar or connecting member 78 isprovided to connect the upper and lower straps 72, 74. As illustrated,the connecting member 78 extends generally vertically in front thepatient's ear and close to the patient's cheek in use. The connectingmember 78 assists with headgear vectoring. For example, the upper strap72 runs horizontally across the patient's cheeks to avoid obstructingthe patient's eyes and to pull the mask directly onto the patient's faceto get the mask to seal, and then the top strap turns upwards over thepatient's ears to secure the mask on the patient's head withoutcontacting the ears (which can be uncomfortable) and also pulls the maskupwards to prevent it from slipping down. The connecting member 78limits relative movement of the upper and lower straps relative oneanother to maintain the positioning and alignment of the upper and lowerstraps 72, 74 to enhance alignment of the vectors for sealing.

Preferably, the cross bar 78 joins the upper and lower straps andmaintains the upper strap in a position away from the field of vision ofthe patient. Additionally, the cross bar may alter the force vectorsapplied by the headgear to the mask system, by allowing the forcevectors to applied to both the upper and lower straps in the samegeneral direction towards the back of the patients head, when in use.Preferably, the cross bar may be adapted as such to allow the upper andlower strap to presented in a generally parallel alignment with eachother. It is noted that the cross bar may not extend generallyvertically, i.e., other configurations are possible.

Additionally, the cross bar may be elastic and flexible and beconstructed of a similar material as to the other portions of theheadgear and straps.

In alternative embodiments, the straps of the headgear may be able toconnect directly to the frame through integrally molded loops, holes orapertures. Also, the headgear may include a strap constructed ofmultiple interlocking hook and loop (e.g., Velcro™) arrangements. Thecorresponding hook and loop pieces may be joined and aligned in a strapconfiguration, which may allow the user or patient to quickly and easilyrelease the strap by separation of the hook and loop interlockinglayers. This may serve as a quick release mechanism.

1.4 Cushion

The cushion 40 is structured to interface with the frame and form a sealwith the patient's nose and mouth in use. In the illustrated embodiment,the cushion is a full-face cushion adapted to engage the patient's facegenerally along nasal bridge, cheek, and lower lip/chin regions of thepatient's face. However, other cushion interfaces are possible, e.g.,nasal.

The cushion may include a two or more wall configuration wherein thecushion comprises membrane and one or more undercushions or supportwalls underneath the membrane.

1.5 Elbow

As shown in FIG. 1-1 for example, the elbow 60 includes a first endportion providing an interfacing structure structured to interface orotherwise attach to the frame 20 and a second end portion including aswivel joint 62 is adapted to be connected to an air delivery tube.

1.5.1 AAV

The elbow is structured to support an anti-asphyxia valve (AAV), whichincludes a flap portion adapted to selectively close a port 64 on theelbow (depending on the presence of pressurized gas).

Alternative embodiments of the AAV are disclosed in PCT Application No.PCT/AU2006/000031, which is incorporated herein by reference in itsentirety.

1.6 Shroud to Frame Connection

The shroud is mounted on the outer surface of the frame, e.g.,preferably with a tight, conforming fit on the frame.

1.6.1 Retaining Mechanism

In the illustrated embodiment of FIGS. 1-1 to 3-2 , the upper headgearrigidizer 50 is connected to the frame 20 by a retaining mechanism orinterfacing structure located on the top end of the frame.

The retaining mechanism includes a taper lock arrangement and aretaining clip arrangement. In addition, an alignment feature isprovided to facilitate alignment and connection of the upper headgearrigidizer to the frame.

As best shown in FIGS. 4-1 to 4-4 and 10-2 , opposing sides of the topend of the frame include a platform 24 which provides a first femaleslot 25(1). In addition, the space between the platform 24 and the outersurface of the frame 20 defines a second female slot 25(2). As bestshown in FIGS. 6-1 to 6-3 and 10-3 , opposing sides of the frameconnecting portion 52 of the upper headgear rigidizer 50 include a tangprotrusion 53 on the underside thereof. The tang protrusion 53 includesa first tang 53(1) and a second tang 53(2) that extends generallytransverse to the first tang. Each tang may taper along its length,i.e., thinner towards its free end.

As shown in FIGS. 10-5 and 10-6 , the tangs 53(1), 53(2) of each tangprotrusion 53 are structured to engage with respective slots 25(2),25(1). As best shown in FIG. 10-5 , the tang 53(1) may include lead-insor guides 56 that curve along their length so as to guide the tang intothe slot and aid assembly.

As best shown in FIGS. 6-1 to 6-3 and 10-3 , the upper portion of theframe connecting portion 52 includes a pair of spaced apart clip arms 65with a locking tab 65(1) provided to each clip arm. In use, each cliparm is adapted to clip onto or overhang the edge of the frame 20, e.g.,with a snap-fit, as shown in FIGS. 3-2, 10-4, and 10-7 .

Specifically, the clip arms are adapted to engage the frame as the taperlocks are progressively engaged. In an embodiment, the clip arms mayprovide an audible click once clipped onto the frame to indicate orconfirm correct assembly.

In the illustrated embodiment, as best shown in FIGS. 10-1 to 10-3 , thealignment feature includes a tab 26 provided to the frame and a slot 66provided to the upper headgear rigidizer 50 and adapted to receive thetab 26 therein when the upper headgear rigidizer is engaged with theframe. However, other alignment features are possible, e.g., one or morealignment markings.

FIGS. 7-1 to 7-5 show an upper headgear rigidizer 50 according to analternative embodiment. In this embodiment, the retaining mechanism onlyincludes the retaining clip arrangement, i.e., no taper lock.

In the embodiment of FIG. 12-1 , the top end of the shroud 250 may beconnected to the frame using a taper lock arrangement and/or a retainingclip arrangement as described above.

1.6.2 Lower Retaining Mechanism

The lower end of the shroud 250 and frame 220 includes a lower retainingmechanism to connect the lower end of the shroud to the frame. In theillustrated embodiment, as shown in FIG. 16-1 , the lower end of theshroud 250 includes a lug protrusion 268 adapted to mate into acorresponding recess or undercut 228 provided to the frame 220 so as toretain the shroud 250 in position. As illustrated, the lug protrusion268 is in the form of a short bump that protrudes outwardly along alength of the shroud edge. For example, the protrusion 268 may extendalong edges “x” of the shroud 250, and/or the protrusion 268 may extendalong edges “y” of the shroud 250 as shown in FIG. 12-2 .

As shown in FIGS. 16-1 and 16-2 , the outer surface of the frame 220 mayinclude a recessed portion or scalloping 229 near the retention feature,which provides a finger grip to allow the patient an improved ability togrip the shroud 250 and disengage the retention feature when disengagingthe shroud from the frame.

1.7 Cushion to Frame Connection

As best shown in FIG. 10-7 , the non-face contacting side of the cushion40 is connected to frame 20 in a tongue and groove relationship. Thetongue 42 of the cushion 40 is inserted within a groove 27 providedalong the perimeter of the frame 20. The tongue and groove relationshipmay also include a locking lip or sealing lip 44 on the cushion 40.

1.8 Ports

As best shown in FIG. 13-2 , the base of the frame may includes twoports 95 positioned so that in use, oxygen or other breathable gas canbe delivered close to the patient's nares or pressure monitoringequipment can be attached. The ports may also be used to attachadditional medical equipment such as pressure or flow sensors. The portsmay be selectively closable or sealable by a ports cap.

While the invention has been described in connection with what arepresently considered to be the most practical and preferred embodiments,it is to be understood that the invention is not to be limited to thedisclosed embodiments, but on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the invention. Also, the various embodiments described abovemay be implemented in conjunction with other embodiments, e.g., aspectsof one embodiment may be combined with aspects of another embodiment torealize yet other embodiments. Further, each independent feature orcomponent of any given assembly may constitute an additional embodiment.In addition, while the invention has particular application to patientswho suffer from OSA, it is to be appreciated that patients who sufferfrom other illnesses (e.g., congestive heart failure, diabetes, morbidobesity, stroke, bariatric surgery, etc.) can derive benefit from theabove teachings. Moreover, the above teachings have applicability withpatients and non-patients alike in non-medical applications.

What is claimed is:
 1. A mask system comprising: a cushion and frameassembly defining a breathing chamber, the cushion and frame assemblycomprising: a cushion portion adapted to form a seal with a patient'sface; a frame portion that is attached to the cushion portion and ismore rigid than the cushion portion, the frame portion comprising anopening; and a vent insert adapted to be supported within the opening inthe frame, the vent insert comprising an array of vent openingsconfigured to discharge gas washout in a radially outward direction;headgear configured to support the cushion and frame assembly on apatient's face; and a shroud provided to the cushion and frame assemblyand adapted to connect the headgear to the cushion and frame assembly,wherein the shroud comprises a central connecting portion with aretaining mechanism structured to connect the shroud to the cushion andframe assembly, the retaining mechanism including a pair of projectionsextending from an inferior side of the central connecting portion andconfigured to be received within corresponding recesses in the cushionand frame assembly, wherein the inferior side of the central connectingportion is concave and is configured to straddle the vent insert whenthe shroud is secured to the cushion and frame assembly so that theprojections of the retaining mechanism are on opposite sides of the ventinsert in use, wherein the shroud further comprises a pair of armportions extending laterally from opposing lateral sides of the centralconnecting portion and configured to extend across the patient's cheeksunder the patient's eyes, wherein each arm portion of the shroud isconfigured to resiliently flex in response to headgear tension, andwherein each arm portion has a multilayer structure that includes atleast one relatively rigid layer and a relatively flexible fabric layer.2. A mask system according to claim 1, wherein the shroud comprises ataper lock arrangement that includes a pair of tang protrusions providedon the inferior side of the shroud adapted to engage with respectiveslots provided to the cushion and frame assembly.
 3. A mask systemaccording to claim 1, wherein the shroud comprises a retaining cliparrangement includes a pair of spaced apart clip arms with a locking tabprovided to each clip arm and adapted to clip onto or overhang an edgeof the cushion and frame assembly.
 4. A mask system according to claim1, wherein the cushion and frame assembly includes a tab and the shroudincludes a slot adapted to receive the tab therein when the shroud isconnected to the cushion and frame assembly so as to align the shroudwith the frame portion.
 5. A mask system according to claim 1, whereinthe shroud includes headgear connectors adapted to attach to headgearstraps.
 6. A mask system according to claim 1, wherein the shroudincludes a second retaining mechanism structured to connect the shroudto an inferior end of the frame portion.
 7. A mask system according toclaim 1, wherein the projections of the retaining mechanism are in theform of lug protrusions adapted to mate into a corresponding recess orundercut provided to the cushion and frame assembly so as to retain theshroud in position.
 8. A mask system according to claim 7, wherein eachlug protrusion is in the form of a short bump that protrudes from anedge of the shroud.
 9. A mask system according to claim 7, wherein thecushion and frame assembly includes a recessed portion or scallopingnear the lug protrusions.
 10. A mask system according to claim 1,wherein the cushion and frame assembly is a full-face cushion and frameassembly.
 11. A mask system according to claim 1, wherein the headgearincludes at least a pair of upper straps, a pair of lower straps, and across bar to connect each pair of upper and lower straps, the cross baradapted to extend generally vertically in front the patient's ear inuse.
 12. A mask system according to claim 1, wherein the vent insert isintegrally formed in one-piece with the frame portion.
 13. A mask systemaccording to claim 1, wherein the vent insert is structured to directexhaust flow up and out from the mask system at an angle between about0-30°.
 14. A mask system according to claim 13, wherein the angle isabout 20°.
 15. A mask system according to claim 1, wherein the cushionand frame assembly is a nasal cushion and frame assembly.
 16. A masksystem according to claim 1, wherein a superior edge of the centralconnecting portion of the shroud is convex.
 17. A mask system accordingto claim 1, wherein a superior edge of each arm portion of the shroud isconcave and an inferior edge of each arm portion of the shroud isconvex.
 18. A mask system according to claim 1, wherein the centralconnecting portion of the shroud is configured to be attached to thecushion and frame assembly so that at least a part of the centralconnecting portion is above the vent openings.
 19. A mask systemaccording to claim 1, wherein the central connecting portion of theshroud is configured to be attached to the cushion and frame assembly sothat at least a part of the central connecting portion is above theopening in the frame portion.
 20. A mask system according to claim 1,wherein the central connecting portion of the shroud is U-shaped.
 21. Amask system according to claim 1, wherein the shroud is configured tomake an audible click when the shroud is attached to the cushion andframe assembly.
 22. A mask system according to claim 1, wherein the ventinsert is removable from the frame portion.
 23. A mask system accordingto claim 1, wherein the central connecting portion and the pair of armportions of the shroud are integrally formed.
 24. A mask systemaccording to claim 1, wherein the projections of the retaining mechanismare in the form of lug protrusions adapted to mate into a correspondingrecess or undercut provided to the cushion and frame assembly so as toretain the shroud in position, wherein each lug protrusion is in theform of a short bump that protrudes from an edge of the shroud, whereinthe cushion and frame assembly includes a recessed portion or scallopingnear the lug protrusions, wherein the cushion and frame assembly is anasal cushion and frame assembly, wherein a superior edge of the centralconnecting portion of the shroud is convex, wherein a superior edge ofeach arm portion of the shroud is concave and an inferior edge of eacharm portion of the shroud is convex, wherein the central connectingportion of the shroud is configured to be attached to the cushion andframe assembly so that at least a part of the central connecting portionis above the vent openings, wherein the central connecting portion ofthe shroud is configured to be attached to the cushion and frameassembly so that at least a part of the central connecting portion isabove the opening in the frame portion, wherein the central connectingportion of the shroud is U-shaped, wherein the shroud is configured tomake an audible click when the shroud is attached to the cushion andframe assembly, wherein the vent insert is removable from the frameportion, and wherein the central connecting portion and the pair of armportions of the shroud are integrally formed.
 25. A patient interfaceconfigured to deliver positive pressure respiratory gas to a patient'sairways, the patient interface comprising: a cushion and frame assemblydefining a breathing chamber, the cushion and frame assembly comprising:a cushion portion adapted to form a seal with a patient's face; a frameportion that is attached to the cushion portion and is more rigid thanthe cushion portion, the frame portion comprising an opening; and a ventinsert adapted to be supported within the opening in the frame, the ventinsert comprising an array of vent openings configured to discharge gaswashout in a radially outward direction; headgear configured to supportthe cushion and frame assembly on a patient's face; and a resilientlyflexible rigidizer configured to connect the headgear to the cushion andframe assembly, the rigidizer comprising a central connecting portionconfigured to secure the rigidizer to the cushion and frame assembly anda pair of arm portions extending from lateral sides of the rigidizer,wherein the central connecting portion of the rigidizer includes aretaining mechanism structured to connect the rigidizer to the cushionand frame assembly, the retaining mechanism comprising a pair of lugsextending from an inferior edge of the central connecting portion andconfigured to be received within corresponding recesses in the cushionand frame assembly, wherein the inferior edge of the central connectingportion of the rigidizer is concave and is configured to straddle thevent insert when the rigidizer is secured to the cushion and frameassembly so that the lugs of the retaining mechanism are on oppositesides of the vent insert in use, wherein each arm portion of therigidizer is configured to resiliently flex in response to headgeartension, wherein each arm portion of the rigidizer is configured toextend across the patient's cheeks under the patient's eyes, and whereineach arm portion has a multilayer structure that includes at least onerelatively rigid layer and a relatively flexible fabric layer.
 26. Amask system according to claim 25, wherein the cushion and frameassembly is a nasal cushion and frame assembly.
 27. A mask systemaccording to claim 25, wherein the central connecting portion of therigidizer is configured to be attached to the cushion and frame assemblyso that at least a part of the central connecting portion is above thevent openings.
 28. A mask system according to claim 25, wherein thecentral connecting portion of the rigidizer is configured to be attachedto the cushion and frame assembly so that at least a part of the centralconnecting portion is above the opening in the frame portion.
 29. A masksystem according to claim 25, wherein the rigidizer is configured tomake an audible click when the rigidizer is attached to the cushion andframe assembly.
 30. A mask system according to claim 25, wherein thevent insert is removable from the frame portion.
 31. A mask systemaccording to claim 25, wherein the central connecting portion and thepair of arm portions of the rigidizer are integrally formed.